Contrary to Mr David, I support the Bill, but it requires the House's scrutiny, and I will suggest several ways in which it can be improved.

May I first say that the measures to reduce the size of the House and equalise the size of constituencies are long overdue? I hear what Opposition Members say, but their arguments do not hold water. The size of the Chamber has changed almost randomly over the past century, and the number of MPs has never been properly tackled. In the current economic climate, we expect organisations in other walks of life to reduce their work force, and for people to work a little harder to take over the responsibilities of their former colleagues. There is no reason why the House should not set an example in that respect.

However, much more importantly, a democratic system in which votes are not of equal value is an insult to democracy. Mr Straw did very well in trying to defend the indefensible for the sake of the Labour party's current electoral advantage, but the fact is that traditional boundaries, consulting local people and community coherence are simply much less important than the integrity of our democratic system. Therefore, contrary to what he says, the arithmetic must be paramount, because one vote, one value is a basic principle of a fair democracy.

Sadly, however, the other part of the Bill will not enhance a fair democracy. The alternative vote system will undermine the very principle of one vote, one value. Many of my hon. Friends, and Margaret Beckett and other Opposition Members, put those arguments very well, and I am sure that they will be enhanced over the coming months. However, we must have a referendum, because it is a matter of honour. The Prime Minister agreed in the coalition agreement to a referendum on AV, but it is a stark reflection of the priorities of the Liberal Democrats that that was their essential first condition of entering into a coalition Government.

I support the coalition because we need the stability it provides, and I appreciate that a referendum is the price for that, but what a high price it is to pay, not only politically, but in simple financial terms. At a time when essential cuts to public spending are about to affect the everyday lives of almost every British citizen, the Deputy Prime Minister insists on spending £100 million on a referendum that nobody outside the House wants nor cares one tiny bit about. How many special needs teachers, cancer nurses or helicopters for Afghanistan could be funded by £100 million? I accept that we must have the referendum, but let it not go unnoticed that we must have it not for the better welfare of the people or the general good of the country, but only for the perceived electoral advantage of the Liberal Democrats.

I support the Bill, but it is the duty of the House to try to improve measures before it, and I will seek to improve this one in two ways. First, the result of the referendum will command far greater respect if it is held on a different day from the national elections in Scotland, Wales and Northern Ireland, as many colleagues have said. The inevitable differential in turnout in different parts of the United Kingdom would leave the authenticity of the referendum open to question.

The second improvement that the Bill needs is in relation to the thresholds. Is it right to bring about constitutional change if only about 15% of the electorate vote for it? The status quo is the status quo because it is the status quo, and changing it should require far more than 15%. That would be wrong. The result of the referendum and the consequent constitutional change will not command respect unless a significant proportion of the electorate support it. It is our duty to improve this Bill, and although I will vote for it this evening, I look forward to seeing a very different Bill on Third Reading.